In regions where water is scarce, and as water becomes scarce in other regions, highly efficient irrigation and fertigation systems that use a minimum of water and fertilizers become increasingly important. A highly efficient irrigation system comprises a porous membrane operating under low pressure (U.S. Pat. No. 7,198,431, co-owned with the present application, the contents of which are incorporated hereinto by reference). This disclosure is directed to a system and method for efficiently delivering an aqueous solution to plants that includes a hydrophilic delivery device, for example, tubing, that has a distal portion positionable adjacent a root system of a plant and a lumen for channeling an aqueous solution from an inlet to the distal portion. At least a portion of the device's wall along the distal portion has a porosity adapted for permitting a flow of the aqueous solution therethrough when acted upon by a surfactant root exudate and/or negative pressure generated by the roots due to water stress. The system further comprises a reservoir that is adapted for holding the aqueous solution therein and is situated in fluid communication with the hydrophilic device's inlet.
At times, however, it is desired to have an option to provide fluid under pressure to the target plants, for example, to germinate seeds, which have not yet developed root systems with which to stimulate the release of the aqueous solution from the tubing or membrane. Under some conditions, it may also be desirable to provide chemigation and/or a gas to the root zone of the plants.
Therefore, it would be desirable to provide a highly efficient system and method for providing multiple fluids to target plants.